NEURAL DEVELOPMENT IN RELATION TO VOCAL BEHAVIOR

这项提议的目的是揭示功能关系 雀形目动物神经解剖改变与发声学习的关系 鸣禽。在斑马雀中，歌唱行为依赖于雄激素， 通常只有雄性才能产下。声乐发展包括 一个感觉阶段，在这个阶段，鸟类记住一个歌唱模型，而一个 鸟类使用听觉反馈进行匹配的感觉运动阶段 他们用自己的声音来表达这段记忆。每个阶段都发生在 一种受限的发育期，在雄性斑马雀身上， 与神经元数量的戏剧性变化和 控制歌曲的神经区之间的连通性。这个 建议的研究有两个具体目标：1)确定如何 歌唱相关脑区的个体发育变化 影响，或受到声音发展的影响，以及2) 评估或更好地确定特定神经区域在发声中的作用 学习。许多拟议的研究将雇用女性， 在孵化后不久就被类固醇雄性化了。这些 雌性在模仿歌声的区域表现出个体发育变化 在雄激素的刺激下，会产生歌声。 重要的是，男性化女性的感觉运动学习可以 通过操纵时间来抵消这些神经变化 雄激素暴露。荷尔蒙调控与行为 将使用分析来确定关键时期是否 感觉学习被发声的雄激素刺激所终止 练习，还是通过与歌曲相关的神经的个体发育变化 地区。还将使用行为分析来确定 神经结构的个体发育变化与 感觉运动学习有助于歌曲学习。光镜 将使用分析和顺行氨基酸放射自显影 以确定雄激素和/或感觉运动学习 增加歌曲控制的神经元数量或投射的变化 原子核。为了识别歌曲特有的神经变化 学习，雄激素对神经结构的影响将被评估 在男性化的女性中，为防止感觉运动而耳聋 学习。最后，电解性和神经化学损伤将是 以加深我们对功能角色的理解 几个歌核。人声之间惊人的相似之处 鸣禽的发展和人类的语言习得 更好地理解歌曲学习的神经机制 可能为学习背后的神经病理提供洞察 一般情况下的紊乱，更具体地说， 语言习得。

The aim of this proposal is to uncover functional relationships between neuroanatomical change and vocal learning in passerine songbirds. In zebra finches, song behavior is androgen-dependent, and normally produced only by males. Vocal development involves a sensory phase during which birds memorize a song model, and a sensorimotor phase when birds use auditory feedback to match their own vocalizations to this memory. Each phase occurs during a restricted developmental period which, in male zebra finches, overlaps with dramatic changes in neuron number and connectivity among the neural regions controlling song. The studies proposed have two specific goals; 1) to determine how ontogenetic changes in the anatomy of song-related brain regions influence, or are influenced by vocal development, and 2) to assess or better define the role of specific neural regions in vocal learning. Much of the proposed research will employ females that have been masculinized by steroids shortly after hatching. These females exhibit ontogenetic changes in song regions that mimic those in males, and develop song when stimulated with androgens. Importantly, sensorimotor learning in masculinized females can be offset from these neural changes by manipulating the timing of androgen exposure. Hormonal manipulations and behavioral analyses will be used to determine if the critical period for sensory learning is terminated by androgenic stimulation of vocal practice, or by ontogenetic changes in song-related neural regions. Behavioral analyses will also be used to determine if overlap between ontogenetic changes in neural structure and sensorimotor learning facilitates song learning. Light microscopic analyses and anterograde amino acid autoradiography will be used to determine whether androgens and/or sensorimotor learning augment changes in neuron number or projections of song-control nuclei. In order to identify neural changes unique to song learning, androgenic effects on neural structure will be assessed in masculinized females deafened to prevent sensorimotor learning. Finally, electrolytic and neurochemical lesions will be performed to further our understanding of the functional role of several song nuclei. Striking similarities between vocal development in songbirds and language acquistion in humans argue that a better understanding of neural mechanisms of song learning may provide insight into neural pathologies underlying learning disorders in general, and more specifically, abnormalities in language acquistion.